Ron Kirby holds a sign while marching in protest of the Patient Protection and Affordable Care Act in front of the U.S. Supreme Court on March 26 in Washington, DC. / Mark Wilson, Getty Images

by Richard Wolf, USA TODAY

by Richard Wolf, USA TODAY

WASHINGTON - President Obama's health care law isn't out of the legal woods yet.

Six months after surviving the Supreme Court by the slimmest of margins, the law still faces lower court challenges to its insurance purchasing mandates, tax penalties, Medicare cost controls, minimum coverage provisions and more.

The cases pose less of a threat to the law than the challenges mounted by 26 states and business organizations last spring. However, the justices' 5-4 ruling to uphold the law on narrow grounds indicated festering opposition both inside and outside the court. That makes a return trip to the high court a possibility in the future.

The latest indication came last month, when the court gave new life to a lawsuit filed by Liberty University in Virginia, a religious institution that objected to the employer and individual mandates for purchasing insurance. The school is one of many religious organizations that object to the inclusion of birth control among the benefits that must be covered.

About 40 lawsuits are challenging the contraception mandate on religious grounds. They come mostly from church-affiliated schools and hospitals opposed to abortion. While the Obama administration in February sought to exempt faith-based groups from having to provide the coverage directly, self-insured employers say they have little choice.

"This is a pressing question that needs to be addressed," says Mathew Staver, dean of the Liberty University School of Law. "It will be a historic clash between the free exercise of religion and a federal law."

Victory on that count could free religious groups that object to covering contraceptives from the law's minimum coverage requirement. The heart of the law - expanding affordable health coverage to millions of Americans and requiring most individuals and large employers to buy insurance - would stand.

Lawsuits that could threaten the entire law haven't advanced as far. Experts say they have less chance of reaching the Supreme Court and toppling Obama's signature domestic policy achievement.

"The cases that challenge the act seem unlikely to present issues that are worthy of Supreme Court review," says Robert Weiner, a former associate deputy attorney general who led the administration's defense of the health care law. "The tough challenges to the statute have been litigated already. The remaining ones are the leftovers."

The appointed board, which is designed to hold down Medicare costs, is not subject to congressional oversight or even "meaningful agency review," says Christina Sandefur, a lawyer with the institute.

The institute also contends that to avoid taxation, individuals have to buy insurance and thereby disclose medical information to insurers and the federal government. That represents an undue burden on liberty and privacy, Sandefur says.

-- A suit filed by the Pacific Legal Foundation, another conservative advocacy group, notes that the law only survived the Supreme Court because Chief Justice John Roberts said its penalties for not buying insurance were taxes. Tax laws, the group notes, must originate in the House, not the Senate.

The health care law was written in the Senate, but with a twist. Lawmakers took a House bill, stripped it of its title and all its provisions, and substituted the health care law.

"We've got to take what we have and attack it under whatever constitutional provision allows us to," says Paul Beard, a foundation attorney. If federal courts buy that argument, he says, "I think the whole thing would have to fall."

-- Oklahoma is challenging the way the law is being implemented. States that have refused to create their own health insurance exchanges, or markets, should not be subject to a provision that subjects employers of 50 or more workers to financial penalties if they don't provide insurance, Attorney General Scott Pruitt says.

The Internal Revenue Service issued that rule in May, even though the health care law specified only that states with their own insurance exchanges would be subject to the employer penalties. Pruitt says that's illegal unless Congress amends the law.

"This is not something that the states take lightly," Pruitt says. "I think people are for the first time saying, 'Wow, you mean there's a tax that's going to be assessed against employers?' "

The Obama administration, while monitoring all the lawsuits, is more focused on getting insurance purchasing exchanges created and expanding Medicaid coverage in the states. Some states are complying, while others are resisting.

"The Supreme Court has ruled, and the Affordable Care Act is the law of the land," says White House spokesman Nick Papas. "We remain 100 percent focused on implementing the law and are confident these remaining cases will be resolved in our favor."

But the legal wrangling won't go away soon. Randy Barnett, a Georgetown University law professor whose contention that the health care law was unconstitutional led to the original Supreme Court challenge, likens the bevy of new lawsuits to the idiom "in for a penny, in for a pound."

"I always thought that if you didn't take out the whole Affordable Care Act, there was then going to be legal issues having to do with parts of it," Barnett says. "Now the courts are in for a pound."